javascript - 正则表达式删除空格

Question

我正在尝试编写一个正则表达式来删除单词开头的空格，而不是后面的空格，并且仅删除单词后面的一个空格。

这是我尝试过的正则表达式:

var re = new RegExp(/^([a-zA-Z0-9]+\s?)*$/);
Output - 
re.test("")
true - required false
re.test(" ")
false
re.test(" word")
false - required word - true 
re.test(" word ")
false - required word - true 
re.test("word ")
true
re.test("word  ")
false - - required word(with single space ) - true 

经验:

看，我必须向后端发送请求，如果

1) key term is ""(blank) no need to send the request. 
2) If key is " string" need to send the request. 
3) If user enter something like this "string    string" need to send the request. 
4) if user enter "string " need to send the request. 
5) if user enter string with a space need to send the request but at the moment he enter another space no need to send the request. 

这件事我试图使用正则表达式来实现。

Answer 1

我认为以下应该为您处理所有空间替换:

var str      = "   this is     my  string    ";
var replaced = str.replace(/^\s+|\s+$|\s+(?=\s)/g, "");
// repl = 'this is my string'